 /*******************************************************************************
  * Copyright (c) 2000, 2006 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.text.edits;

 import java.util.ArrayList ;
 import java.util.List ;

 import org.eclipse.jface.text.BadLocationException;
 import org.eclipse.jface.text.IDocument;

 /**
  * A move target edit denotes the target of a move operation. Move
  * target edits are only valid inside an edit tree if they have a
  * corresponding source edit. Furthermore a target edit can't
  * can't be a direct or indirect child of its associated source edit.
  * Violating one of two requirements will result in a <code>
  * MalformedTreeException</code> when executing the edit tree.
  * <p>
  * Move target edits can't be used as a parent for other edits.
  * Trying to add an edit to a move target edit results in a <code>
  * MalformedTreeException</code> as well.
  *
  * @see org.eclipse.text.edits.MoveSourceEdit
  * @see org.eclipse.text.edits.CopyTargetEdit
  *
  * @since 3.0
  */
 public final class MoveTargetEdit extends TextEdit {

     private MoveSourceEdit fSource;

     /**
      * Constructs a new move target edit
      *
      * @param offset the edit's offset
      */
     public MoveTargetEdit(int offset) {
         super(offset, 0);
     }

     /**
      * Constructs an new move target edit
      *
      * @param offset the edit's offset
      * @param source the corresponding source edit
      */
     public MoveTargetEdit(int offset, MoveSourceEdit source) {
         this(offset);
         setSourceEdit(source);
     }

     /*
      * Copy constructor
      */
     private MoveTargetEdit(MoveTargetEdit other) {
         super(other);
     }

     /**
      * Returns the associated source edit or <code>null</code>
      * if no source edit is associated yet.
      *
      * @return the source edit or <code>null</code>
      */
     public MoveSourceEdit getSourceEdit() {
         return fSource;
     }

     /**
      * Sets the source edit.
      *
      * @param edit the source edit
      *
      * @exception MalformedTreeException is thrown if the target edit
      * is a direct or indirect child of the source edit
      */
     public void setSourceEdit(MoveSourceEdit edit) {
         if (fSource != edit) {
             fSource= edit;
             fSource.setTargetEdit(this);
             TextEdit parent= getParent();
             while (parent != null) {
                 if (parent == fSource)
                     throw new MalformedTreeException(parent, this, TextEditMessages.getString("MoveTargetEdit.wrong_parent")); //$NON-NLS-1$
 parent= parent.getParent();
             }
         }
     }

     /*
      * @see TextEdit#doCopy
      */
     protected TextEdit doCopy() {
         return new MoveTargetEdit(this);
     }

     /*
      * @see TextEdit#postProcessCopy
      */
     protected void postProcessCopy(TextEditCopier copier) {
         if (fSource != null) {
             MoveTargetEdit target= (MoveTargetEdit)copier.getCopy(this);
             MoveSourceEdit source= (MoveSourceEdit)copier.getCopy(fSource);
             if (target != null && source != null)
                 target.setSourceEdit(source);
         }
     }

     /*
      * @see TextEdit#accept0
      */
     protected void accept0(TextEditVisitor visitor) {
         boolean visitChildren= visitor.visit(this);
         if (visitChildren) {
             acceptChildren(visitor);
         }
     }

     //---- consistency check ----------------------------------------------------------

     /*
      * @see TextEdit#traverseConsistencyCheck
      */
     int traverseConsistencyCheck(TextEditProcessor processor, IDocument document, List sourceEdits) {
         return super.traverseConsistencyCheck(processor, document, sourceEdits) + 1;
     }

     /*
      * @see TextEdit#performConsistencyCheck
      */
     void performConsistencyCheck(TextEditProcessor processor, IDocument document) throws MalformedTreeException {
         if (fSource == null)
             throw new MalformedTreeException(getParent(), this, TextEditMessages.getString("MoveTargetEdit.no_source")); //$NON-NLS-1$
 if (fSource.getTargetEdit() != this)
             throw new MalformedTreeException(getParent(), this, TextEditMessages.getString("MoveTargetEdit.different_target")); //$NON-NLS-1$
 }

     //---- document updating ----------------------------------------------------------------

     /*
      * @see TextEdit#performDocumentUpdating
      */
     int performDocumentUpdating(IDocument document) throws BadLocationException {
         String source= fSource.getContent();
         document.replace(getOffset(), getLength(), source);
         fDelta= source.length() - getLength();

         MultiTextEdit sourceRoot= fSource.getSourceRoot();
         if (sourceRoot != null) {
             sourceRoot.internalMoveTree(getOffset());
             TextEdit[] sourceChildren= sourceRoot.removeChildren();
             List children= new ArrayList (sourceChildren.length);
             for (int i= 0; i < sourceChildren.length; i++) {
                 TextEdit child= sourceChildren[i];
                 child.internalSetParent(this);
                 children.add(child);
             }
             internalSetChildren(children);
         }
         fSource.clearContent();
         return fDelta;
     }

     //---- region updating --------------------------------------------------------------

     /*
      * @see org.eclipse.text.edits.TextEdit#traversePassThree
      */
     int traverseRegionUpdating(TextEditProcessor processor, IDocument document, int accumulatedDelta, boolean delete) {
         // the children got already updated / normalized while they got removed
 // from the source edit. So we only have to adjust the offset computed to
 // far.
 if (delete) {
             deleteTree();
         } else {
             internalMoveTree(accumulatedDelta);
         }
         return accumulatedDelta + fDelta;
     }

     boolean deleteChildren() {
         return false;
     }
 }

